Synthesis And Modification Of LiNi_1/3Co_1/3Mn_1/3O₂Cathode Material For Lithium-ion Batteries

Layer-structured LiNi1/3Co1/3Mn1/3O2compound has been considered as a promisingcandidate of next-generation cathode materials to replace LiCoO2for rechargeable lithiumion batteries due to its large capacity and stable structure.The cathode material of LiNi1/3Co1/3Mn1/3O2was prepared by Spray drying in thispaper. SEM results show that LiNi1/3Co1/3Mn1/3O2are spherical. XRD analyses indicatethat the LiNi1/3Co1/3Mn1/3O2was formed with the standard of layered α-NaFe02crystaldiffraction; The steady discharge capacities of the material cycled at0.1C rate are at about152mAh·g-1in the voltage range2.5~4.3V and the capacity retention is about88.9%after25cycles. Cyclic voltammograms experiment showed that the first cycle volt-amperecurve of oxidation and reduction peaks position almost as the second, which provedLiNi1/3Co1/3Mn1/3O2cathode material has good reversibility of Li+embedded.LiNi1/3Co1/3Mn1/3O2cathode material was coated with AlF3on the surface by sol-gelmethod. The initial capacity of LiNi1/3Co1/3Mn1/3O2decreased slightly, however the cyclingstability was improved by reducing the increase of film resistance and charge transferresistance.94.4%of initial capacity retained after25cycles; Li(Ni1/3Co1/3Mn1/3)1-xMxO2(M=Al、Mg) cathode material was prepared by Spray drying. It has good electrochemicalperformance when x is0.01.The capacity is148and144mAh·g-1after25cycles andcapacity retention is96.3%and98.1%.Nanofibers of LiNi1/3Co1/3Mn1/3O2prepared by electrospinning method. SEM resultsindicate that the nanofibers are mainly good filaments before the sintering and good barafter the sintering. The initial capacity is165mAh·g-1and the capacity retention is about92.3%after25cycles.